Only a few years ago, the exchange of chemical signals, or pheromones, between bacteria was considered the exception rather than the rule. A small number of examples of cell-cell signaling had been well described, including the bioluminescence regulatory systems of Vibrio fischeri and Vibrio harveyi, the conjugal transfer system of Enterococcus faecatis, the production of antibiotics by Streptomyces spp., and the development of multicellular fruiting bodies of Myxococcus xanthus. It was assumed that cell-cell communication was not used by most bacteria. Cell-cell signaling in bacteria was considered at that time to be an interesting subject of research, but not one of fundamental importance to human health. In the past ten years, an enormous number of new examples of inter-bacterial signaling have been reported. These systems regulate a number of processes as diverse as virulence, sporulation, antibiotic production, DNA exchange, and development of multicellular structures. It is now understood that, in fact, most bacteria communicate with one another using secreted chemical molecules. Inter-cellular communication systems are fascinating because they allow bacteria to coordinately control the gene expression of the entire community. This ability fundamentally blurs the distinction between unicellular and multicellular forms of life. Several of these signaling systems are also extremely important to human health, because they regulate the virulence determinants of bacterial pathogens. Because of the recent explosion in research in the area of cell-cell communication in bacteria and its newly discovered role in eliciting human disease, the ASM hosted a conference devoted to cell-cell signaling during the summer of 2001. This meeting was so well received by its participants that the ASM became committed to provide an ongoing venue for this topic, and will host a second conference in July of 2004. The conference will be held at Banff, Alberta, in the Canadian Rockies. The NIH generously supported the first ASM sponsored meeting on this topic, and has supported many of the investigators that study cell-cell communication in bacteria, and it is hoped that the NIH will provide financial assistance for this upcoming conference.